The continued proliferation of colonies of red imported fire ants Solenopsis invicta are becoming a serious problem in the United States. From their place of origin in Argentina and Brazil, they have spread from sea ports along the Gulf of Mexico across the Southeastem States of the USA from Texas to Florida and northward to a latitude along the southern border of Tennessee. They are playing havoc with many important utilities including electric power distribution and telecommunication systems as well as heating and air conditioning systems and traffic control systems. Fire ants are attracted to electrical circuits and they can cause failures in transformers, cables, connectors and related electrical hardware. They also pose a serious threat to livestock and small animals lying on the ground. Thousands of fire ants can cover a small animal on the ground and sting it repeatedly. The stings can cause a newborn calf to be blinded and die. Fire ants can also be very hazardous to people in the outdoors. It is very easy to step in or near a mound and be quickly covered with fire ants. They generally cause a localized allergic reaction on the area of the skin punctured by their stinging. Their sting is quite painful, and its effects can last for hours. Some individuals suffer a severe allergic reaction that can lead to anaphylactic shock, which can be fatal if not treated promptly. Small children and elderly people are particularly susceptible to serious injury from fire ants.
The control of fire am colonies in the environment has been attempted through the use of insecticides that either kill the insects directly on contact or result in a disruption of their reproductive cycle. These chemicals are being used more extensively and they are beginning to pose a serious threat to the quality of ground water systems in highly concentrated population areas. The poisons that kill on contact only eliminate a small portion of the fire ants exposed on the surface of the ground. Many of these ants remain below ground, in the mound, and merely move to a new location and reestablish a new colony. Baits that result in a disruption of the fire ant's reproductive process are more effective in eliminating a colony, but they are slow to achieve results and recent experience indicates that the fire ants may be developing immunities to some of these chemicals that may reduce their long term effectiveness. A more recent idea involves importing a natural predator of the fire ant from its place of origin. The predator is a small gnat that lays it's eggs in the eyes of fire ants. Some experiments are being planned with its introduction in the USA, but the additional side effects of introducing yet another insect are unknown.